Wifi Dropouts when Wemos D1 Controlled Relay Connected to Merlin Garage Door Controller

Hi All,

One of my projects is a “Super Smart Garage Door Controller”. I’m using an Ultrasonic Sensor to get the open closed distance, and have finally managed to get it stabilised to a good point.

But when i connect the “Remote Trigger” onto the Dry Contacts of the Relay controlled by the Wemos D1, i begin to get Wifi Dropouts and the whole thing becomes unstable.

Any ideas?

  • I’m thinking of moving the relay to be closer to the Door Terminals?
  • Is there anything else i can do to further isolate the door trigger wire?

I have added a simplified diagram.

Hi there, I want to achieve the same thing. I also have a spare wemos D1 mini kicking about.
I’d be curious as to where you’re at with it now.
I was expecting to simply either tie the merlin garage door lifter to either ground or VCC (whatever the lifter is expecting) via the wemos when the door needs to change position. You’re driving a solenoid to do this?
What ultrasonic sensor are you using to detect the door position?
Did you look at putting sensors on the bottom and top of the panel glide slots rather than ultra-sonic?

I came across this:https://khaz.me/cheap-and-easy-home-assistant-garage-door-control/

I also have a camera in my garage, was wondering if I could somehow use a deepstack integration or something to use some form of visual analysis (along with presence detection). Not helpful at night though…

What type (solid, stranded) and gauge (24 awg, 16 awg) wire are you running from the relay to the garage door controller trigger contacts? Door installers typically use thin, very small gauge, solid-core two-conductor cable. If your wire is heavier gauge, or stranded, that might be causing issues.

Another solution might be to add a small ceramic capacitor on the Wemos D1 Mini between GND and USB/5V.


Its been a bit of a challenge. The Ultrasonic sensor is too unstable for the accuracy and responsiveness i required. As i wanted to use it to detect whether the door was moving and set the door to a particular position. In the end i got it mostly working using a rotary encoder for the position. The HC-SR04 i used to calibrate the rotary encoder on every close in case of missed steps.

But then… the rotary encoder fell apart. I guess it wasn’t really meant for the kind of use.

Anyway, i’m now tinkering around with a TOF sensor to replace the HC-SR04. However, i will need to redesign everything for an ESP32 as i need a board with a second UART as the 8266 isn’t known for reliable software serial.

That’s an excellent update. Thank you!
It’s food for thought.
Appreciate it.